Impacts of Agricultural Soil NOx Emissions on O3 Over Mainland China

Abstract Regional ozone (O 3 ) pollution has currently become an urgent air pollution problem in China. Nitrogen oxides (NO X ) are key precursor pollutants for O 3 formation. However, pollution control policies have generally neglected or simplified the impacts of soil NO X emissions in rural regions. This study aims to evaluate the effect of soil NO X emissions on O 3 in agricultural areas of China based on high‐resolution soil NO X emission inventory and the WRF‐Chem air quality model. We first validate the simulation result of the O 3 concentration with surface O 3 observations over China using the selected optimal physicochemical scheme. After that, four scenarios are designed to simulate and analyze the regional sensitivity of O 3 to soil NO X emissions and to quantify the effect of soil NO X emissions on O 3 concentration. The results indicate that as soil NO X emissions increase, the overall spatial pattern does not change notably over mainland China, but the O 3 concentration increases remarkably in the northwest and northeast of China. Additionally, we discover that changes of O 3 concentration across mainland China differ substantially among regions. Our results highlight the effect of soil NO X emissions on air quality in agricultural areas. The control of O 3 pollution in China should take into account the comprehensive consequences of various emission sources, as well as their regional differences.